Core bit



- 0. DUDA CORE BIT Filed July 5, I927 m YlIlE l l l l m \h INVENTOR. (0mm Dida- BY mm? ATTORNEY Patented Oct. 28, 1 930 i UNITED? STATES PATENT OFFICE.

OSWALD DUDA, OF

nous'ron, TEXAS, ASSIGNOR To REED ROLLER BIT COMPANY,

HOUSTON, TEXAS, A ,CORPORATTON OF TEXAS CORE BIT Application filed m 5, 1927. Serial no. 203,493.

This invention relates to deep well drill- '15 the invention, Fig. 1 is a'sectional side elevation of the assembled bit; Fig. 2 is a bottom plan view thereof; and Fig. 3 is a fragmentary side elevation partly in section showing the lower end of the bit at 90 degrees to Fig. 1. 0 The core bit disclosed in the drawings embodies the elements usually to be foundin bits of this type. The head is indicated at 1, and is joined to the drill stem '2 by an intermediate member 3. The core pipe 4 extends upwardly within the stem 2 and receives depending plug 6, saidplug having the usual ports 6 to permit the escape of gas, water,

etc. confined in said pipe, and being beveled to permit the passage of slush downwardly 0 between pipe 4 and stein 2 and thence through courses 1 of head 1.

Referring now to the elements which constitute the preferred embodiment of this 1nvention: I r

i It is well-known to those skilled in the art that the use of core bits has been unavoidably attended by lateral movement thereof; that such movement produces an eccentric rotation of the bit, with respect to the core as an axis, whi'ch'inevitably reduces the size of the core; and that such reductionis frequently so great that the core catchers now 1n use fail to engage the core.

To effect removal of the core, this invention provides a new and improved core-engaging member or core catcher 7 comprising a tubular body having a split lower end 7 beveled to fit the beveled bore 1 of head. 1 and having internal teeth 7 and an upper end red'uced to permit extension thereof into herethe lower section 5 of pipe 4 and provided with aplurality ofintegral 'spring dogs 7".

L The downward movement of the core catcher is limited by the tapered bore 1 of the head and the upward movement thereof by the annular flange 5" of section 5, and also by the lower-end of said section against which the shoulder of said catcher, formed by the reduced upper end, is adapted to abut.

Then the bit moves downwardly over the core, the core catcher, which normally rests in the lowermost position illustrated inFig. V

1 because of the force of gravity, comes in contact with the core and is thereby moved upwardly until'its upward movement is arrested by the annularfiange 5 and the bottom of section 5, as shown in Fi n 3. The spring dogs 7' are forced outwardly by the core. When the bit has descended a predetermined distance, and is withdrawn from the hole, the spring dogs 7, engaging the core,

initially prevent simultaneous upward movement of the catcher 7, and the split lower end 7 of said catcher is collapsed by the tapered bore 1 of the head to bring the teeth 7, into engagement with the core. The resistance offered by the core to the upward movement of catcher 7 is then overcome, and the core,

firmly held by thedogs 7 and the embracing teeth 7", is carried upwardly with the bit. The dogs thus not only engage the core, but also cause engagement of the core by the lower end of'the catcher. v

The roller cutters now in use in core bits are so constructed and disposed that cores are frequently shattered by the crushing teeth thereof. I v

This invention provides a bit embodying a pair of oppositely disposed cylindrical cutters 8 mounted on pins 9 which extend downwardlyand inwardly toward'the longitudinal axis of the head; and a pair of substantially frusto-conical cutters 10 whose axes are at substantially right angles to the longitudinal axis of the head. The cutters 8 are provided with the usual peripheral cutting teeth. The cutters 10, however, which remove the formation immediately adjacent the core, are provided with crushing teeth 10 which insure rotation of the cutter, and shaving teeth 1O".

shaving tooth, said cutter having shattering teeth extending substantially at right angles from said shaving tooth toward said base end.

In testimony whereof, I hereunto aflix my signature.

OSWALD DUDA.

11, fitting the inwardly tapered opening in the head, projects inwardly to support tapered bushing 12 and to be engaged by bolt 14. The cutter 10 is held on said bushing by I the bolt 14, the bolt 14 being provided with a suitable washer, as shown. And the bushing and cutter have raceways therein for the reception of balls 13. The parts will be securely locked together when the bolt 14 is tightened, and provide a strong and easily assembled support upon which the cutters 10 will be freely revoluble.

It is to be understood that the hereinafter appearing claims are not limited to the preferred embodiment shown, and that various changes may be made without departure from the scope thereof.

I claim:

1. A core bit having ahead, a plurality of substantially frusto-conical cutters mounted on said head, the axes of said cutters being at substantially right angles to the longitudinal axis of the head, and a plurality of cylindrical cutters on said head, the axes of said cylindrical cutters being inclined downwardly and iIHVlLIdly toward the longitudinal axis of the 2. A core bit having a pair of oppositely disposed substantially cylindrical cutters, the axes of said cutters being inclined downwardly and inwardly, and a pair of oppositely disposed substantially frusto-conical cutters, the axes of said frusto-conical cutters being at substantially a right angle to the longitudinal axis of the bit and the base ends of said frustoconlcal cutters being outermost.

3. A core bit having a core opening and a roller cutter, said cutter having a circumferentially disposed shaving tooth adjacent said opening, and shattering teeth extending substantially at right angles to said shaving tooth.

4. A core bit having a core opening and a substantially frusto-conical roller cutter adjacent said opening, the base end of said cutter being outermost, the inner end of said cutter having a circumferentially disposed shaving tooth.

5. A core bit having a core opening and a substantially frusto-conical roller cutter adjacent said opening, the base end of said out ter being outermost, the inner end of sald cutter having a circumferentially disposed 

